Allow user to partially update Sentinel config

defaults/main.yml

@@ -4,7 +4,7 @@ redis_version: 2.8.24
 redis_install_dir: /opt/redis
 redis_dir: /var/lib/redis/{{ redis_port }}
 redis_config_file_name: "{{ redis_port }}.conf"
-redis_download_url: "http://download.redis.io/releases/redis-{{ redis_version }}.tar.gz"
+redis_download_url: "https://download.redis.io/releases/redis-{{ redis_version }}.tar.gz"
 
 redis_protected_mode: "yes"
 # Set this to true to validate redis tarball checksum against vars/main.yml
@@ -117,10 +117,17 @@ redis_hz: 10
 #   io-threads-do-reads yes
 redis_config_additional: ""
 
+## Redis cluster configs
+redis_cluster_enabled: false
+redis_cluster_node_timeout: 15000
+# Prevent slave to be promoted as a master in case of auto-failover 
+# only works in version 4.x and above
+redis_cluster_slave_no_failover: "no"
+
 ## Redis sentinel configs
 # Set this to true on a host to configure it as a Sentinel
 redis_sentinel: false
-redis_sentinel_protected_mode: "yes"
+redis_sentinel_protected_mode: "no"
 redis_sentinel_dir: /var/lib/redis/sentinel_{{ redis_sentinel_port }}
 redis_sentinel_bind: 0.0.0.0
 redis_sentinel_port: 26379
@@ -129,15 +136,20 @@ redis_sentinel_pidfile: /var/run/redis/sentinel_{{ redis_sentinel_port }}.pid
 redis_sentinel_logfile: '""'
 redis_sentinel_syslog_ident: sentinel_{{ redis_sentinel_port }}
 redis_sentinel_oom_score_adjust: 0
-redis_sentinel_monitors:
-  - name: master01
-    host: localhost
-    port: 6379
-    quorum: 2
-    auth_pass: ant1r3z
-    down_after_milliseconds: 30000
-    parallel_syncs: 1
-    failover_timeout: 180000
-    notification_script: false
-    client_reconfig_script: false
-    rename_commands: []
+redis_sentinel_monitors: []
+# Set this to true if you update the configuration via runtime
+# e.g: registering master to monitor via command-line instead manually edit the config file
+redis_sentinel_runtime_monitor_master: false
+# Example:
+# redis_sentinel_monitors:
+#   - name: master01
+#     host: localhost
+#     port: 6379
+#     quorum: 2
+#     auth_pass: ant1r3z
+#     down_after_milliseconds: 30000
+#     parallel_syncs: 1
+#     failover_timeout: 180000
+#     notification_script: false
+#     client_reconfig_script: false
+#     rename_commands: []

tasks/sentinel.yml

@@ -102,13 +102,86 @@
     - redis_sentinel_pidfile != '""'
     - not sentinel_piddir.stat.exists
 
+- name: check if sentinel is running
+  command:
+    cmd: systemctl status sentinel_{{ redis_sentinel_port }}
+  ignore_errors: true
+  changed_when: false
+  register: sentinel_service_status
+
+- name: run flushconfig to rewrite config file from current configuration
+  command:
+    cmd: "redis-cli -p {{ redis_sentinel_port }} SENTINEL FLUSHCONFIG"
+  when: sentinel_service_status.rc == 0
+
+- name: check if sentinel config file exists
+  stat:
+    path: /etc/redis/sentinel_{{ redis_sentinel_port }}.conf
+  register: _config_file
+
+- name: backup existing config file
+  copy:
+    src: /etc/redis/sentinel_{{ redis_sentinel_port }}.conf
+    dest: /etc/redis/sentinel_{{ redis_sentinel_port }}.conf.{{ ansible_date_time['date'] }}
+    owner: "{{ redis_user }}"
+    mode: 0640
+    remote_src: true
+  when: _config_file.stat.exists
+
 - name: create sentinel config file
   template:
     src: redis_sentinel.conf.j2
     dest: /etc/redis/sentinel_{{ redis_sentinel_port }}.conf
     owner: "{{ redis_user }}"
     mode: 0640
   notify: "restart sentinel"
+  when:
+    - not redis_sentinel_runtime_monitor_master or
+      not _config_file.stat.exists
+
+- name: update static configuration in config file
+  blockinfile:
+    path: /etc/redis/sentinel_{{ redis_sentinel_port }}.conf
+    insertbefore: "### STATIC CONFIG STOP HERE ###"
+    owner: "{{ redis_user }}"
+    mode: 0640
+    backup: yes
+    block: |
+      # redis-sentinel {{ redis_version }} configuration file
+      # sentinel_{{ redis_sentinel_port }}.conf
+
+      daemonize {{ redis_daemonize }}
+      protected-mode {{ redis_sentinel_protected_mode }}
+      dir {{ redis_sentinel_dir }}
+      pidfile {{ redis_sentinel_pidfile }}
+      port {{ redis_sentinel_port }}
+      bind {{ redis_sentinel_bind }}
+
+      # Security
+      {% if redis_sentinel_password %}
+      requirepass {{ redis_sentinel_password }}
+      {% endif %}
+
+      {% for master in redis_sentinel_monitors -%}
+      sentinel monitor {{ master.name }} {{ master.host }} {{ master.port }} {{ master.quorum|d('2') }}
+      {% for option in ('auth_pass', 'down_after_milliseconds', 'parallel_syncs', 'failover_timeout', 'notification_script', 'client_reconfig_script') -%}
+      {% if master[option] is defined and master[option] -%}
+      sentinel {{ option|replace('_', '-') }} {{ master.name }} {{ master[option] }}
+      {% endif %}
+      {% endfor -%}
+      {% if master['rename_commands'] is defined -%}
+      {% for command in master['rename_commands'] -%}
+      sentinel rename-command {{ master.name }} {{ command }}
+      {% endfor -%}
+      {% endif -%}
+      {% endfor -%}
+
+      logfile {{ redis_sentinel_logfile }}
+      syslog-enabled {{ redis_syslog_enabled }}
+      syslog-ident {{ redis_sentinel_syslog_ident }}
+      syslog-facility {{ redis_syslog_facility }}
+  notify: "restart sentinel"
+  when: redis_sentinel_runtime_monitor_master == true
 
 - name: add sentinel init config file
   template:

templates/redis.conf.j2

@@ -53,6 +53,16 @@ min-slaves-max-lag {{ redis_min_slaves_max_lag }}
 masterauth {{ redis_password }}
 {% endif -%}
 
+{% if redis_cluster_enabled %}
+# Cluster
+cluster-enabled yes
+cluster-config-file nodes-{{ redis_port }}.conf
+cluster-node-timeout {{ redis_cluster_node_timeout }}
+{% if redis_version.split('.') | first | int >= 4 -%}
+cluster-slave-no-failover {{ redis_cluster_slave_no_failover }}
+{% endif -%}
+{% endif -%}
+
 # Security
 {% if redis_password -%}
 requirepass {{ redis_password }}
@@ -104,4 +114,4 @@ aof-rewrite-incremental-fsync yes
 {% if redis_config_additional|length -%}
 # Additional
 {{ redis_config_additional -}}
-{% endif -%}
+{% endif -%}

templates/redis_sentinel.conf.j2

@@ -1,3 +1,4 @@
+### STATIC CONFIG START HERE ###
 # redis-sentinel {{ redis_version }} configuration file
 # sentinel_{{ redis_sentinel_port }}.conf
 
@@ -31,3 +32,5 @@ logfile {{ redis_sentinel_logfile }}
 syslog-enabled {{ redis_syslog_enabled }}
 syslog-ident {{ redis_sentinel_syslog_ident }}
 syslog-facility {{ redis_syslog_facility }}
+
+### STATIC CONFIG STOP HERE ###